Picosecond diode-pumped 1.5 μm Er,Yb:glass lasers operating at 10-100 GHz repetition rate

Stable ultrafast laser sources at multi-GHz repetition rates are important for various application areas, such as optical sampling, frequency comb metrology, or advanced high-speed return-to-zero telecom systems. We review SESAM-mode-locked Er,Yb:glass lasers operating in the 1.5 mu m spectral region at multi-GHz repetition rates, discussing the key improvements that have enabled increasing the repetition rate up to 100 GHz. We also present further improved results with shorter pulse durations from a 100 GHz Er,Yb:glass laser. With an improved SESAM design we achieved 1.1 ps pulses with up to 30 mW average output power. Moreover, we discuss for the first time the importance of beam quality deteriorations arising from frequency-degenerate higher order spatial modes in such lasers.